Switching mechanism



May 25, 1937. E. L. DUNN SWITCHING MECHANISM Original Filed Sept. 28. 1927 she FG INSULATION INSULATION INSULATION INSULATION SSI INSULATION FIGZ INVENTOR ATTORNEY Patented May 25, 1937 UNITED STATES PATENT OFFICE SWITCHING MECHANISM Edward L. Dunn, Livingston, N. J., assignor to Otis Elevator Company, New York, N. Y., a corporation of New Jersey 3 Claims.

This application is a division of application Serial No. 222,480, filed September 28, 1927 which became Patent No. 2,032,475 on March 3, 1936.

The present invention relates to switching 5 mechanism and especially to electromagnetic switching mechanism of the latching type.

In the parent application above referred to, a system of control for elevators is disclosed in which push buttons are. provided for controlling the operation of the car. In controlling the operation of the car, the push buttons act through floor relays. When a push button is pressed, the floor relay is operated and latched in operated condition, permitting the push but- 5 ton to be released. The invention is directed to switching mechanism particularly suitable for floor relays in elevator systems having push but ton control but which may be utilized for other purposes.

The principal featurev of the invention is to provide electromagnetic switching mechanism which is mechanically latched in one position and which is of simple construction and reliable in operation.

Other features and advantages of the invention will become apparent from the specification and appended claims.

In the drawing:

Figure 1 is a side elevation of an embodiment of the switching mechanism; and

Figure 2 is a plan view of the same with parts in section.

According to the preferred arrangement, the switching mechanism comprises two pairs of contacts, 12, I3 and l4, 15, the characters 12 and 14 designating the stationary contacts and the characters 13 and 15 designating the movable contacts. If the switching mechanism is used as a floor relay in an elevator control system such as that disclosed in the parent application, contacts 12, 13 are for controlling the slow down and stopping of the car and will be termed stop contacts while contacts 14, 15 are for controlling the starting and running of the car and will be. termed start contacts. The stationary contacts are of the same construction, each comprising a contact piece 5l'l secured in a contact holder 5IB. The stem 520 of the contact holder extends through the panel and at the rear thereof is provided with nuts 52! for securing the holder to the panel and for connecting the contact in the system. The movable contacts also are of the same construction and only one of them, namely, contact 13, will be described. A bracket 522 is secured to the panel, as by a bolt 523. This bracket has two outwardly extending sides 524 between which a contact arm 525 is mounted. The lower end of the contact arm is bent to conform to a pivot pin 526 extending through the sides of the bracket. An aperture 52'! is provided in the bracket through which a pin 528 extends, the panel 516 being provided with a recess 530 to receive the head of the pin. This pin extends through an aperture 53! in the con tact arm and is provided with a cotter pin 532 on its outer end to limit the outward movement of the arm about its pivot. the contact arm is formed with an inclined portion 533. Above the inclined portion, the contact arm terminates in a hook 534. This hook consists of a vertical portion 535 and a horizontal portion 535, the width of the horizontal portion being considerably reduced. A contact blade 53! also is mounted on pin 528, being provided with an aperture 538 through which the pin extends. The. contact blade is also provided with a slot 539 through which the horizontal portion 536 of the contact arm extends. The contact piece of stationary contact 12 is disposed in the path of movement of the contact blade 531. A spring 540 is arranged on pin 528 for biasing the contact blade to disengaged position. The nuts 54! for bolt 523 at the rear of the panel also serve for connecting the movable contact in the system.

A pair of rollers 542 are provided for moving the movable contacts to engaged position. These rollers are arranged on the inner end of armature 543 for cooperation with the contact arms 525. The armature 543 is channel shaped and the roller pin 544 for the rollers extends through the legs 545 of the. channel. The armature is fulcrumed on a stand 543 as by means of a bolt 541 extending through the channel legs, the web 548 of the channel being provided with a slightly elongated opening 550 through which the stand extends. The stand is supported by the magnet frame 55l secured to panel 516, as by bolts 552. This frame extends outwardly from the panel and, in addition to supporting the stand 546, supports magnet cores 553 and 554, one on each side of the stand. The outer core 553 is provided with a magnet coil 10 while the inner core 554 is provided with a magnet coil I90. Coil I0 is for causingthe engagement of the contacts and will be termed the closing coil. Coil I90 is for causing the disengagement of the contacts and will be termed the reset coil. The outer end of the armature 543 is provided with a weight 555 Above the pin 528,

arranged between the legs and secured thereto as by pins 556, preferably of non-magnetic material. An opening 551 is formed in the outer end of the armature through the web 548. This opening extends into a recess 558 formed in the weight 555, this opening being such as to expose a portion of one of the non-magnetic pins. This arrangement is provided to permit core 553 to extend upwardly into the armature when the armature is in switch closed position. Similarly, the inner end of the armature is provided with an opening 56!] to permit core 554 to extend upwardly into the armature. when the armature is in reset position. A pin 56! of non-magnetic material extends between armature legs 545 above the opening 560.

In operation, it will be assumed that the various parts of the floor relay are in the positions illustrated. Upon the pushing of the button for which the relay is provided, closing coil is energized. As a result, the outer end of the armature is attracted and the armature is rocked clockwise about its fulcrum. During this movement, rollers 542 roll up the inclined portions 533 of their respective contact arms, causing counterclockwise movement of these arms about their pivots, the weight 555 assisting in causing this movement. The contact blades 53! are carried with the contact arms, springs 54!] yielding to permit the movement. As a result, the contact blades are moved into engagement with the contact pieces of the stationary contacts. As the counter-clockwise movement of the contact arms continues, the contact blades are slidably pivoted thereon against the force of springs 540, resulting in positive rubbing contact engagement. As the rollers roll onto the vertical portions 535 of the contact arms, the armature is brought to a stop by the engagement of the exposed pin 556 with the top of core 553. As the parts are constructed and arranged so that the armature is brought to a stop on or beyond the dead center point of the contact arms with respect to the pivot point of the armature, the contacts are latched in engagement. Thus, upon the closing coil 10 being deenergized as a result of the pressure on the push button being released, the contacts remain in engagement.

Upon the reset coil I90 being energized, the inner end of the armature is attracted and the armature is rocked counter-clockwise about its fulcrum. The exposed pin 556, being of nonmagnetic material, prevents the armature being held in switch closed position due to residual magnetism. During this movement, springs 540 act to cause the separation of the contact blades from the contact pieces of the stationary contacts. These springs also assist in restoring the armature to reset position. The contact blades are brought to rest by the engagement of the contact arms with the cotter pins 532 while the armature is brought to rest by the engagement of pin 56l with the top of core 554. This pin, being of non-magnetic material, prevents the armature being held in reset position by the effect of residual magnetism when attracted by the closing coil 10.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A switch comprising; a pair of stationary contacts; a pair of contact blades, each for engaging one of said contacts; a pair of pivoted arms, one for operating each contact blade, each arm having an inclined portion and an end portion; resilient means for biasing each blade and operating arm into position with the blade disengaged from its stationary contact; a pivoted armature; a pair of rollers, one for each operating arm, carried by said armature; an electromagnet adapted, when energized, to cause movement of said armature in one direction about its pivot, said armature causing movement of said rollers up the inclined portions onto the end portion of their respective arms until dead center is reached, said rollers, during said movement up the inclined portions of their contact arms, moving said arms about their pivots and said contact blades into engagement with their respective stationary contacts against the force of said resilient means, said blades, after their engagement with their stationary contacts, slidably pivoting on their respective operating arms against the force of said resilient means to cause rubbing contact engagement; and an additional electromagnet adapted, when energized, to cause opposite movement of said armature about its pivot, said resilient means acting, during such movement, to cause the separation of the contact blades from their stationary contacts.

2. A switch comprising; a pair of stationary contacts; a pair of contact blades, each for engaging one of said contacts and each provided with an aperture; a pair of pivoted arms, one for operating each contact blade, each arm being provided with an inclined portion and a hook portion, a portion of the hook portion extending into the aperture of its contact blade to form a guide therefor; a pair of springs, one for each blade and its operating arm, each biasing its blade and operating arm into position with the blade disengaged irom its stationary contact; a pivoted armature; a pair of rollers, one for each operating arm, mounted on one end of said armature; an electromagnet adapted, when energized, to cause movement of said armature in one direction about its pivot, said armature causing movement of said rollers up the inclined portions onto the hook portion of their respective arms until dead center is reached, said rollers, during said movement up the inclined portions of their contact arms, moving said arms about their pivots and said contact blades into engagement with their respective stationary contacts against the force of said springs, said blades, after their engagement with their stationary contacts, slidably pivoting on their respective operating arms against the force of said springs to cause rubbing contact engagement; and an additional electromagnet adapted, when energized, to cause opposite movement of said armature about its pivot, said springs acting, during such movement, to cause the separation of the contact blades from their stationary contacts.

3. A switch comprising; a pair of stationary contacts; a pair of contact blades, each for engaging one of said contacts and each provided with a pair of apertures; a pair of pivoted arms, one for operating each contact blade, each arm being provided with an aperture aligned with one of the apertures of its contact blade, an inclined portion and a hook portion, a portion of the hook portion extending into the other aperture of its contact blade to form a guide therefor; a pair of pins, one for each blade and its operating arm, each pin extending through the aligned apertures of its blade and contact arm to form a guide therefor; a pair of springs, one for each blade and its operating arm, each being mounted on one of said pins and biasing its blade and operating arm into position with the blade disengaged from its stationary contact; a pivoted armature; a pair of rollers, one for each operating arm, mounted on one end of said armature; an electromagnet adapted, when energized, to cause movement of said armature in one direction about its pivot, said armature causing movement of said rollers up the inclined portions onto the hook portion of their respective arms until dead center is reached, said rollers, during said movement up the inclined portions of their contact arms, moving said arms about their pivots and said contact blades into engagement with their respective stationary contacts against the force of said springs, said blades, after their engagement with their stationary contacts, slidably pivoting on their respective operating arms against the force of said springs to cause rubbing contact engagement; and an additional electromagnet adapted, when energized, to cause opposite movement of said armature about its pivot, said springs acting, during such movement, to cause the separation of the contact blades from their stationary contacts.

EDWARD L. DUNN. 

